21121431121 has 8 divisors (see below), whose sum is σ = 24145804800. Its totient is φ = 18098814048.

The previous prime is 21121431103. The next prime is 21121431143. The reversal of 21121431121 is 12113412112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21121431121 - 2⁹ = 21121430609 is a prime.

It is a super-2 number, since 2×21121431121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121431151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 413281 + ... + 461566.

It is an arithmetic number, because the mean of its divisors is an integer number (3018225600).

Almost surely, 2^21121431121 is an apocalyptic number.

It is an amenable number.

21121431121 is a deficient number, since it is larger than the sum of its proper divisors (3024373679).

21121431121 is an equidigital number, since it uses as much as digits as its factorization.

21121431121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878303.

The product of its digits is 96, while the sum is 19.

Adding to 21121431121 its reverse (12113412112), we get a palindrome (33234843233).

The spelling of 21121431121 in words is "twenty-one billion, one hundred twenty-one million, four hundred thirty-one thousand, one hundred twenty-one".